Device for forming cup-shaped articles



Nov. 8, 1960 L. A. THOMA DEVICE FOR FORMING CUP-SHAPED ARTICLES 2 Sheets-Sheet 1 Filed Dec. 2, 1957 NDV. 8, 1960 THQMA 2,959,110

DEVICE FOR FORMING CUP-SHAPED ARTICLES Filed Dec. 2, 1957 2 Sheets-Sheet 2 as a? 2 /2 2,959,110 DEVICE FOR FORMING CUP-SHAPED ARTICLES Leonard A. Thoma, Chicago, Ill., assignor to Western Electric Company, Incorporated, New York, N.Y., a corporation of New York Filed Dec. 2, 1957, Ser. No. 699,957

3 Claims. (Cl. 93-60) This invention relates to devices for forming cupshaped articles and more particularly to devices for drawing cups from non-metallic materials.

One of the prime disadvantages of devices used in prior practice for drawing paper or other non-metallic cups has been that the sides of the drawn cup tend to expand after removal from the drawing dies, thereby changing the shape of the cup. With this problem in mind, one of the objects of this invention is to provide a device for drawing paper cup-s in such a manner that the cups retain their shape after removal from the forming device.

Another object of this invention is to provide a device for drawing a paper cup having a conical bottom which tends to return to a flat configuration to thereby prevent expansion of the sides of the cup.

One embodiment of the present invention may include a preforming die having a counterbored recess or nest for supporting a circular element of heavy paper and also having a conical or tapered throat and a vertical cylindrical bore extending downwardly from the center of the nest. A punch having a concavely recessed lower end cooperates with a spring-loaded support or forming member having a convex upper surface to form the central portion of the element into a concavely curved configuration and to then force it downwardfrom the nest through the throat and the bore, which preforms the element. The punch and support member continue downward and carry the preformed element into position between a plurality of radially movable die segments which are then cammed radially inward to form the cup. The concavely curved bottom tends to return to a fiat configuration to thereby prevent expansion of the sides of the cup after removal from the forming device.

Other objects and advantages of the invention will become apparent by reference to the following detailed description and the accompanying drawings illustrating a preferred embodiment of the invention, in which Fig. 1 is a vertical section of a device embodying the principles of the present invention and showing the various parts of the device in unactuated positions;

Fig. 2 is a fragmentary view of the device showing the device showing the various elements in actuated positions;

Fig. 3 is a sectional view taken on line 33 of Fig. 1 illustrating a positioning of the die segments which are moved radially inward to form the cup; and

Fig. 4 is a perspective view of a completed cup.

Referring now in detail to the drawings, a preforming die 11 having a circular recess or nest 12 is shown supporting, in this recess, a circular element 13 of a nonmetallic material, such as a heavy waxed paper, which is to be drawn into a cup. The die 11 is secured to guide rods 15 which are slidably mounted on a plate 23 secured to a ram 20 movably mounted above a base 16 and actuated by a fluid cylinder 22 and which are provided States Patent O 2,959,110 Patented Nov. 8, 1960 with compression springs 18 to normally urge the die 11 downward from the plate 23.

The ram 20 carries a punch 21 which cooperates with a support or forming member 32 to grip the element 13 therebetween. The forming member 32 is secured to a shaft 34 slidably mounted in an aperture in the base 16 and urged upward by a compression spring 36. The upper end of the member 32 is provided with a convex surface 33 which cooperates with a concave recess 26 in the lower end of the punch 21 to hold the element 13 and to form the bottom of the element 13 into the concavely curved configuration illustrated in Fig. 2. The punch 21 and the forming member 32 then move the paper element 13 to force it downward from the nest 12 through a conical or tapered throat 24 and a cylindrical bore 25 in a depending portion of the die 11. As the element 13 passes through the throat 24 and the bore 25, it is preformed; i.e., it is partially drawn into a cup.

A hold-down member 27 slidably secured to the plate 23 by rods 28 is urged downward by compression springs 30 mounted on the rods 28 to retain the element 13 in the recess 12 as the punch 21 is moved downward. A frustoconical surface 37 on the hold-down member 27 cooperates with a conically counterbored surface 38 between the recess 12 and the throat 24 to engage an outer peripheral portion of the element 13 to iron it as the element is moved into and through the throat 24 and the bore 25.

The base 16 is provided with a cylindrical recess 40 having at its upper end a conical camming surface 41 adapted to engage cam surfaces 44 of a plurality of die elements 46 mounted for radial movement in the recess 40 and held therein by an apertured plate 47 secured to to the base 16. The spacing between adjacent die elements 46 is such that (i.e., small enough that) the die elements are moved into engagement with each other when moved radially inward, thereby preventing radial Operation In operating the device, the element 13 is positioned in the recess 12 and the ram 20 is actuated to lower the punch 21. The hold-down member 27 and the die 11 moves downward with the punch 21, the forming member 32 remaining stationary as it is passed by the bore 25 and the throat 24 and then cooperating with the punch 21 to form the central portion of the element into the concavely curved configuration illustrated in Fig. 2. The movement of die 11 is then stopped by its engagement with the die elements 46, the springs 52 being such that they resist further downward movement of the die 11.

Upon further downward movement of the ram 20, the punch 21 begins to move the element 13 downward through the die 11, the spring 36 holding the forming member 32 in engagement with the element to retain the concavely curved configuration therein, and into the recesses 57 in the die elements 46. The forming member 32 then engages the die elements 46, and the force applied by the punch 21 forces the die elements downward against the action of the springs 52. Downward movement of the die elements 46 causes them to move radially inward, the camming surface 41 being in engagement with the camming surfaces 44 to apply a heavy vertical sides of the cup. Upon further upward movement of the-ram20,- the-various elements are moved into the positions shown inFig. 1. The above procedure is then repeated with another flat element 13 positioned in the recess 12.

His to be understood that the above-described arrangementsare simply illustrative of the application of the principles of this-invention. Numerous other arrangements maybe readily devised by those skilled in the art which will embodythe principles of the invention and fall withinthe spirit and scope-thereof.

What is claimed is:

1. Adevice for forming cups, comprising a base, a ram movably mounted-above the base, means for actuating the ram, a die movably supported by the ram and having a recess for receivinga disc ofmaterial tobe formed into a cup, saiddie having a tapered aperture intersecting the recess, a punch carried by the ram and having a concave end forforcing the disc through the die to partially drawsaid disc into a cup, a forming member mounted on the base and having a convex surface for cooperating with the punch to bend a portion-of the disc into a concavely curved configuration, a plurality of radially movabledie elements movably mounted on the base and adapted to surround the partially formed cup and the end of the punch, and means on the base for moving the'die elements radially inward on the partially formed cup and the end of the punch.

2. A device for forming-a cup from a disc of material, comprising a base, a ram movably mounted above the base, a die movably supported by the ram and having a recess for'receiving a disc of material to be formed into a cup, said die also having a tapered aperture extending therethrough from said recess, a punch carried by the ram and having a recessed lower end for forcing the disc through the tapered aperture in the die to partially form the disc into a cup, a forming member resiliently mounted on the base and having a convex surface for cooperating withthe punch to form a concavely curved portion in the disc, a plurality of radially movable die elements positioned about the forming member and adapted to surround the partially formed cup and the end of the punch for compressing the cup against the punch, and means on the base for moving the die elements radially inward.

3. A device for forming a disc into a cup, comprising a base, a ram movably mounted above the base, a die movably supported on the ram and having a recess for receiving a disc to be. formed into a cup, said die. also havinga tapered aperture intersecting said die recess, a punch carried bythe ram and having a concave lower end'for engaging a central portion of the disc to force the disc through the tapered aperture in said die to partially form said disc, a forming-member resiliently mounted on the base in alignment with the punch and having a con vex upper surface for cooperating with the punch to form a concavely curved boss in the central portion of the disc, means for actuating the ram to move the punch and disc through the tapered aperture in the die to partially-forrn the disc into a cup, a plurality of radially movable die elements resiliently mounted in a cylindrical recess in the base and adapted 'to surround the end of the lowered punch, the recess in said base having a conical camming' surface, eachsaid die element having a tapered surface. engaging said camming surface, and means for resiliently supporting the die elements in the recess in said base, said punch moving the partially formed cup into position between and into engagement with the die elements and forcing saiddie elements downward whereby engagement of the conical surface with the tapered surfaces forces the die elements radially inward to squeeze the cup on the punch.

References Cited in the file of this patent UNITED STATES PATENTS 

